It is known that a tendency exists for an underwater portion of a vessel hull or structure to become increasingly fouled over time to the extent that eventually a significant layer of material, including in some circumstances living organisms, accumulates on the underwater portion of the vessel hull or structure.
If such fouling is not removed from the vessel hull or structure, significant problems can occur, including damage to the vessel hull or structure and, in the case of a marine vessel, a reduction in seafaring performance of the vessel. In addition, some living organisms can be noxious and, if transported to other locations, can be dangerous to local species.
Uncontrolled in-water cleaning can release chemical and biological contaminants into the local environment, and for example may stimulate the release of reproductive propagules, or plant and animal fragments capable of regeneration.
In order to avoid release of such contaminants into the local marine environment, conventional vessel hull cleaning techniques have involved removing the vessel from the water, and subsequently cleaning the vessel hull. However, this approach is expensive and time consuming.